Mulliken, NPA and ESP derived charge analyses have been carried out along the minimal energy reaction path using the IRC method for (CHCl)-C-1 and (CCl2)-C-1 insertion into C-H bonds of methane and ethane. Transition states (TS) of these reactions have been investigated at HF, MP2, CCSD (for methane only) and DFT levels with 6-31g (d,p) basis set. G3MP2 calculations have significantly improved the energetics. The occurrence of TSs either in the electrophilic or nucleophilic phase has been identified through NBO charge analyses in addition to the net charge flow to the carbene. (c) 2006 Elsevier B.V. All rights reserved.